Prof. H. James-Clark on the Animality of the Ciliate Sponges. 13 



11. The structure of the ramified and net-hke configuration 

 of the viscid substance depends chiefly upon the degree of force 

 of the rotating mantle-fluid, the form of the cellulose capsule, 

 the point of attachment of the viscid mass on the cellulose cap- 

 sule and its relative position to the axis of rotation of the mantle- 

 fluid, and, lastly, upon its state of cohesion. 



12. There is no essential diff*erence between the rotating, 

 circulating, and rotato-circulating currents of the cells; in all, the 

 rotating mantle-fluid is to be placed in the foreground; in it 

 alone we can recognize the direct influence of the unknown 

 causes of the currents, and this everywhere acts in the same way. 



13. The other constituents of the "mantle-layer" exposed 

 to the mechanical influence of the rotating mantle-fluid cause 

 the current of the vegetable cell to vary in outward appearance ; 

 they will also, of course, present varying obstacles to it according 

 to circumstances. Among the phenomena of this nature I may 

 indicate that in the cavities formed between the resting masses 

 of the viscid substance the rotating mantle-fluid may come to 

 perfect rest, and that then molecular movements of free granules 

 are detected in such cavities, — further, that iw Hydrocharis morsus 

 ranee the rotating mantle-fluid is divided into two regular rotating 

 currents, running down separated from each other by a distinct 

 piece traversing the cavity of the cellulose capsule, — and, lastly, 

 that by means of such impediments at the rounded poles of the 

 cellulose capsule reflux movements of the currents of the most 

 various kinds may be produced. 



14. Motory phenomena from which the existence of a con- 

 tractile activity in the viscid substance or in the other consti- 

 tuents of the cell-contents might be deduced, are entirely wanting 

 in the plant-cells with currents investigated by me. 



15. With regard to the movements of currents in the cells of 

 plants, the first thing to be done is to discover the causes by 

 which the rotating movements of the " mantle-fluid '' are pro- 

 duced. But no physical or chemical processes by which this 

 rotating movement might be brought about have hitherto been 

 detected in the cells of plants. 



IV. — Conclusive Proofs of the Animality of the Ciliate Sponges , 

 and of their Affinities with the Infusoria flagellata. By H. 

 James-Clark, A.B., B.S.* 



Before I proceed to the main point in question in this article, 

 I wish to say a word in regard to the group of animals, viz. the 

 Protozoa, of which I am fully convinced the Spongia ciliata 

 are a part. 



* From * Silliman's American Journal, Nov. 1866. 



